Electromagnetic apron feeder



March 3l, 1925. 1,531,372

J. P. BETHKE ELECTROMAGNETI C APRON FEEDER Filed March 24, 1925 2 Sheets-Sheet 1 INVHVTOR.

- BEM ATTORNEY? 1,531,372 J. P. BETHKE ELECTROMAGNETIC APRON FEEDER AFiled March 24, vw23 2 lshew-sheet 2 Fig. l

Byi

A YTORNEYJ vPatented Mar. 31, 1925.

. the crushing mills y` -removin t e harder In Figures 'Fand 2 .UNITED STATES vPArENr orner.

Jenn r. maxx, or'xLwAUxnE, WISCONSIN, AssIeNon T q mAGNE'i'rc MANUFAC c, Timms-Ico., or nmwnpxna, wisconsin.

-mncrnomeimrrc Arnon naman Application med mmh 24,

To all whomt may Be it known that I JOHN P. Bn'rnrm a citizen of the United gtates, residing at Milwaukee, county ofk Milwaukee, and State of Wisconsin, have invented new and useful Improvements' in Electromagnetic lApron Feeders, of which the following is a specificationnl Y This invention relates to improvements in apron feeders of the general type employed for feeding rock, ore, and other materials to crushing mills. f

The object of this invention is to provide an apron feeder withe'ective means -for separating magnetizable material from the material to lbe crushed, thereby rotecting CON/6em.'

portions of the` material, inc uding fra.g, ments'of'iron and steel broken or disenga 4from the machinery employed in handlingl such materials. A further` object of vthis invention visftol so combine a magnet with an apron feeder as to lconvert the lfeeder into an' effective: magnetic separator-without radical change in structure erdesign.

In the drawings: .c '1, Figure 1 is'a sectional view of an apron feeder embodying the invention herein.. claimed, the section being takento a vertical plane which includes the axis of the s rockets shaft at the delivery end ofthe fee er, 1., Figure 2 is asecti'onal Aview-on 1ine,2-2, ofFlgureLi 'i I f e 3 is' a view showin an lembodiment of the invention;

infwhie Va stationary' magnet isiutili-zed Figure 4 is ja plan view of the magiietf. or electro-magnetic battery shown' in Figure 3. t.

Like parts are identied by the same .ref.y erence characters 'throughout they several views. n

y the apron is of ordinary type andfcomprises'a succession of dat, plates or barsl having cylindrically curved or arcuate margins 2f and 3 which interlap with the marginsof la 'acent bars'to form an endless belt. At t eir respective ends.;

the 41"afre supported by sprocket chains 4 w "cli'ta'vel about endy sprocket wheels 5, the `connection between the-plates and the s rocket chains being made substantially a ong the longitudinalVv center line of the l. plates The llnks'of the s prockety chains ave'V their central portionsprovided with j `the thickness of the A.steel zapon.

lthe ksuccessive 192e. .semina 627,291.

arms for this purpose. ,Y Butl the connectni pms of the ,links are.pro vided with ro ers V 8 "which travel, .along supporting beams 9S 'lxhe spaces between the teeth of the sprocket wheelsuare adapted to Vrece' e the rollers 8. .'1he.,1nargins2v and 3 of apron plates are curved, about the axes 0I.

the plns 7..- i Y,

-At the delivery .end IofV the conveyor the sprocket Wheels' are mounted upon a shaftr 10 .which may serve .as "the driving shaft, and between Athese sprocket wheels an electro-magnetic pulley 11; is .mounted on` the same shaftand has a diameter substantially equal :tofi thatothe, pitch circle 'of the s rocket whe'els, w lereby the periphery of t .into close proximity to the plates4 1 as t ey r as's about ythe shaft 10 without .necessarily eing in lactual contactwiththe plateav The pulleyma;'y be nLe'tters atentl rif-theUnited States to John l.PV` Bethke No. 1,334,117, dated Jul 12, 1921, orto John P. Bethke and R.

Stearns, No,I 1,407,051, dated February' 21,

1922. .Magneti` pulleys in which the vwindings are, protected by sleeveso coverings 12, composed of non-magnetic material, are preferablyemployed'sincethe apron is composedtof ma'netizable material, ille., steel es a distribution of` the :lines vof. magnetic force similar to' that described which provi iitheaboiie mentioneddtent No. 1,407,051.

1n agpulley having a diameter of .about `18 vinchesffthe pole plecesjhave a thickness of abouti two inches, which is about ei rht times herefore,

Ia small. ercentage of the lines of magnetic kforce Wi saturate the apron'an'd the lattery becomesmagnetio over substantially the .entirecareaiof'that portion, in proximity .t0

.the pulley without reducingx the effective tpe strengthofthe iield beyond l apron. The abuttmg lends Q ,fjhe spools, composing the magnetic,A ulley,,.. constitute' annular pole piecesan :thespools lare so wound that pole pieces will be of opposite polarity. I

It will be observed thatthe exciting wind- 1 ings A,13 of the magnetic pulley are Wholly protected `lby the spools 14 and the coveri 12, but ,that the pulley is .well ventilated, t e spools .being spaced from the shaft and from each' other to form an annular ventilating passage y15 and cawitliesfl extending between .los

'iL-hc spools. The sprocket wheels are of Skelel, composing the apron and the pole pieces.

ton iormation with openings 17 to 'allow Therefore, the magnetic pulley disclosed in circulation of air through the: pulley. Figures 1 and 2 is preferred.. lt is also preM f sprocket wheels also carry the load of ferred for thereason that its structure prf theepron and the material thereon,thereby vided for a more effective distribution of I0 relievingl the. magnetic pulley from strain magnetic `energy for the reasons above ssd melting it possible to wholly support the stated. spools Arorn the skeleton end Wells 18 of the While l have described the apron sections pulley. The pulley, however, is preferably 1 as being forme-.dof steel, it will be nntler- .9 splinetl et 29 to the shaft 10, whereby fric'- stood that any rigid material suitable for 75 tion avoided if any portion of the apron feeding heav f masses o? rock or ore may be should come in contact with its periphery. employed. teel is preferably used for the I lfhs mailles it possible to bring the pulley reason above stated, i. e.. thslt it becomes i extremely close proximity to the apron, magnetic in the vicinity oi' the pulley, and,

to substantial Contact with it without therefore, more ecctive in holding meg- 3U ting the pulley to material pressure netizeble materiel. lt also distributes the snel without developing friction iA actual lines of magnetic force whereby magnetizcontact results. l y able material midway between the pole The operation of apron eedet'isfslwhnil '.piec'es may'dbe Vattracted directly toward the f) customary to feed materiel-wtlifefoiilfaipron nlonga linefsubstentially yperpendicu- 95 in 'irregular masses or piles,` thus forming -lar to surface. upon the epron a layer of material .of vary- I claim: ing thickness, and frequently of @thickness 1. An apron feeder having an endless or depth of one footer mo But notwithconveyor a ron composed of flexibly formed f standing the thickness of thisflayer `u'fhehl substanti y rigicl sections otmagnetizable 9" would. ordinarily make magnetic I`separation material, in combination with o magnet, the diliicult, il not impossible, it has been found. eld ofnwhich includes the delivery end of that thejnventiouabove described; con be 'the conveyor. utilized Owing t0 the cascading Irlltxte#` '2, The combination of an apron feeder l?? 'rial across the delivery end of theconyyor," havingaconveyor apron composed of flexibly 95 i. e., over the magnetic ul1ey,-,whereby the connected metallic sections, and on electro- .rnater'ial forms a' thin layer over llfesu magnet, the field of which includes the deofthe pulley along that rtion ofthe-a ron V'livery end ofthe conveyor. extending downwardl rom a. vertical p onev 3. vAnl pron feeder hevingg endless con 35 through the axis of .t e pulleyto e horizon'-4 veyor apron composed of fl ibly connected tsl plane which includes such" axis'. The metal olsections, in com "ation with supmsterial not onlyl cascades in Ytheforrn'of a f portipg'lwheels for said sections, anden thin layer 'but t e component ports of$he electromagnetic pulley inter sed between laye-r also separate lon tndinallyf as theflnofV .the vvheels' at the deliveryengof the apron 4o tion of the falling bo ies aooplll'tes It 1S, with its periphery in close proximity to the therefore, possib e to provide @the apron apron. feeder with stationary .side wallsftjor guards 4.1An-apron-feeder having an endless con y to allow the material to cculimllt 0I! `Voyer-apron., in combination with suppllA the apron to a considerable depththroughf ing wheels 'for seid apron, und au electro- 45 out ille-Width of the apron. L v magnetic pulley interposed between the Referring DOW -t- O Figures 3. *L 47-1# `.W1 1l whcels'et the delivery en@L of the apron with nl? @USP/lied that. 1n place of :te mgnetl@ its periphery in close proximity to the apron. 'pulley iilisclosed in Figures -1 @sind 2, I may said pulley hsving annuler pole pieces of only ly battery of e ectroniagnetlc s cols successively opposite polarity, said support- 2T :nul 29 connected by avyoke 30. ach ingwheels being atlepted to support the con m5 spoel has its coreprovidediwith an extended veyor apron independently 0i seid pulley, segmental pole piece 31, and the successive whereby to relieve seid pulley from the spools in the set or battery are oppositely weight of materiel being carried by salti Wound, the pole pieces being thereby .of opapron. n 55 posite polarity. The shaft 10 of the apron 5. The combination 'with :in electromagn@ conveyor extends throughvapei'tures in these net' having pole pieces of opposite polarity. pols pieces 31, whereby the shaft 13o-operates of a. feeding apron having sup orting vil/ith a. non-magnetic bar 32 in supporting wheels for supporting seid apron in-l epencl" w the battery of magnets. .The yoke 30 rests ently of said pole pieces to revolve :it its .Q t@ upon the ber 32 as shown. delivery end about said pole pieces '.,eaclr im The curved surfaces 35 of the pole pieces pole piece having e curved fece substanll lie in'an are concentric with the shaft 10 tielly in en sro concentric with that along and in close proximity to the apron. In this which the apron travels. construction it is, of course, desirable to pi 6. The combination with en electromagvent Contact between the members or pls notie pulley kering annuler pele pieces ci -nectic pulley having annular pole pieces of successivelyV opposite polarity, a feeding apron independently vsupported to travel at its delivery end about the axis of th(` pulley, y

and means for Ventilating the pulley.

8. The combination with an electromagnet-io pulley having a series of annular magy netic windings and intervening pole pieces of oppo ite pol'arity, and a covering for the windingscomposed of magnetizable ma! terial, of an apron feeder comprising a series of flexibly joined magnetizable inemberaymqa s., for supporting said feeder for travel hbdut the pulley in close proximity thereto, 'said supporting means being adapted to relieve the pulley from weight.

9. The combination with an electromagnetic pulley having annular pole pieces of opposite polarity, and intervening spacers of magnetizable material, formin with the pole pleces, a continuous eyhn er, of an endless conveyor apron arranged to travel' over said pulley apron, supporting Wheels at each end of the pulley, and a common actuating means for the Wheels and pulley.

l0. An apron feeder having an endless conveyor cornprisinl I magnetizable plates hingedly secured together, in combination with supporting wheels for said conveyor, and an electro-magnetic pulley interposed betweenthe wheels at the delivery end of the conveyor, said plates bein supported in theirl travel about the pulley in close proximity' thereto.

11. The combination of an apron feeder havin an endless conveyor comprising magnetiza le plates each having arcuate margins transversely of the conveyor and interlapped with the margins' ol' adjacent plates, said plates being each hingedlyV secured to its ladjacent plates, and an electro-magnetic pulley at the delivery end of the conveyor.

JOHN P. BBTHKE. 

